The only problem right now, if you want to build, is getting a barrel (assuming you install the barrel yourself). Buddy waited 4 months for a barreled upper assembly. You can find uppers at gun shows, but they're m4gery length, and run $550 and up - without the bolt carrier and bolt. I saw a parts kit for $130 the other day at a show, and a stripped lower was $180 (cheapest one I saw). Add in everything, and you're talking over 1000 - plus some potentially long wait times.